Integration of component devices of a consumer electronics product is desirable to reduce form factor. Integration often results in size reduction because multiple devices become part of one integrated system. The integrated system itself can then be progressively reduced in size over time. Integration of multiple devices into one system is complex and made more complex in cases where each device is of a different type and has different manufacturing requirements.
For example, microelectromechanical systems (MEMS) acoustic sensors (e.g. MEMS microphones) are utilized in applications having size and power constraints, such as in mobile devices. Presently, MEMS microphones suffer from a number of drawbacks such as noise, interference and non-linearity. Noise can result from the various components forming the microphone such as amplifiers (e.g., preamplifiers), analog to digital converters (ADC), and the power supply. External low-frequency or high-frequency sources may cause interference. MEMS microphones are particularly vulnerable to RF interference. Non-linearity of the membrane and the electronic circuit that processes the signal generated by the MEMS can distort the acoustic signal and thus, degrade the performance of the system. In conventional systems, a single amplifier is used to amplify the electrical signal generated by the membrane or electro-acoustic transducer. MEMS microphones may use more than one membrane for transduction to achieve a higher signal-to-noise ratio. Such systems traditionally rely on a single amplifier to amplify the input received from one or more acoustic membranes.
However, such systems provide no immunity against external interference, supply noise and non-linearity. In particular, non-linearity severely limits the maximum signal that the system can handle with high fidelity.